There are various types of volatile memories formed on semiconductor substrates. Among them, a SRAM (static random access memory) is able to achieve high-speed operation and is utilized for a cache memory and the like.
A memory cell in the SRAM includes a flip-flop circuit formed of multiple MOS transistors. Information is stored in the flip-flop circuit.
Reduction in the cell size of the SRAM can contribute to downsizing of an electronic device including the SRAM such as a calculator.
Note that 2008 Symposium on VLSI Technology Digest of Technical Papers, p. 106-107, 2008 discloses techniques related to the SRAM.